While officials are still investigating who was behind the deadly bombings at the Boston Marathon, President Obama made it clear on Tuesday that authorities are still unclear whether domestic or foreign actors are responsible for the attack.

But one message from domestic terrorism experts is clear: Most of the evidence points against an antigovernment group being responsible for the attack. Several militia groups, who fiercely and sometimes violently fight to keep their Second Amendment rights, have come out against the bombings in Boston.

While some of the factors surrounding the Boston bombings could point to these groups—a simplistic homemade bomb, causing mass casualties, falling on Tax Day—other factors don’t add up. For many of these groups, the date that most matters to them is not Tax Day or Patriots’ Day or even Hitler’s birthday, but the anniversary of the Waco siege (pictured below). On April 19, 1993, 76 people died when a radical, antigovernment sect’s compound in Texas burnt to the ground after days of firefights with federal officials. When Timothy McVeigh bombed the federal building in Oklahoma City in 1995, killing 168 people, it fell on the anniversary of the Waco raid, which he cited as a motivation for the attack.

Other members of antitax groups, who believe in a constitutional right notto pay a federal income tax, have attacked the Internal Revenue Service in previous instances. In February 2010, a man flew a small plane into the IRS building in Austin, Texas, killing himself and one other person.

And in that last incident, the pilot who crashed his plane in the IRS building left a long, rambling manifesto that concluded:

I saw it written once that the definition of insanity is repeating the same process over and over and expecting the outcome to suddenly be different. I am finally ready to stop this insanity. Well, Mr. Big Brother IRS man, let’s try something different; take my pound of flesh and sleep well.

The communist creed: From each according to his ability, to each according to his need.

The capitalist creed: From each according to his gullibility, to each according to his greed.

For many journalists I’ve spoken with today, this ignorance is tortuous. The identification of the attacker(s) and the reasons for the attack will likely have enormous political (and potentially geoplitical) ramifications, which will vary greatly depending on whether the attacker(s) is domestic or foreign, acting alone or as part of an organization. We’re standing on the verge of a very important national conversation about something, and we have no idea what it is.

To translate: By “a very important national conversation,” of course Dylan Byers means, another chance to turn a horrible tragedy into a political talking point.

On the flip-side, as Allahpundit warns, linking to the same National Journal article we quoted above:

But wait. Didn’t Eric Rudolph bomb random civilians at a concert during the Olympics, an event kinda sorta like the Boston Marathon? Sure, says National Journal — but he wasn’t part of a group. Their real argument here, in other words, isn’t that a domestic terrorist didn’t do it, it’s that if one did, he probably wasn’t being sponsored or supported somehow by an organization. (BuzzFeed actually dialed up a few militias this morning and got denunciations of the Boston attack across the board.) Note that well, because if the bomber turns out to be domestic, the idea that he doesn’t represent any larger movement will instantly go straight into the toilet.

I'm not grasping the purpose of the above? Are we urging the FBI not to investigate US residents? Do we want the stealth bombers to hit Riyadh? Why do we care what alleged "experts" think? And what is the horrible bad thing about following evidence, leads and tips in order to catch perps that I've forgotten?